The present invention generally relates to the field of lighting devices. More particularly, the present invention relates to a method and apparatus for providing a high temperature corrosion resistant light bulb shield.
Typical lighting devices and illumination systems use a shield mounted to provide functional and decorative attributes. A bulb shield directs light in a desired direction. Bulb shields are typically made by stamping 300 series stainless metal, and then plating the metal with a layer of nickel. The bulb shield may then be chrome plated to enhance the outer appearance. Following the plating process, the inside portion of the bulb shield may be painted to reduce reflectivity of light rays. These materials typically discolor (they oxidate) when exposed to temperatures near or above approximately 350xc2x0 C. Such temperatures are common in vehicle lighting.
The discoloration or oxidation results in a yellowish-brown outside surface color which tarnishes the appearance of the bulb shield. An outer portion of the bulb shield or an inner portion of the bulb shield may discolor and deteriorate due to the exposure to such high temperatures. The deterioration of the surface of the bulb shield limits the lifetime of the bulb shield.
The bulb shield may be used as a decorative fixture positioned in front of a lighting device. The discoloration of the bulb shield may eliminate the decorative possibilities of the bulb shield. The bulb shield may be placed through an electroplating process to provide a metal coating on the surface of the bulb shield. The metal coating may provide an added layer of protection for the bulb shield, but existing metal coating compositions lack high temperature protection. Known metal coating compositions may also deteriorate due to an exposure to high temperatures.
The use of providing a coating on lamp and headlight reflectors is generally known in the art. For example, U.S. Pat. No. 4,085,248 to Zehender (hereinafter xe2x80x9cZehenderxe2x80x9d) discloses a method to apply a corrosion protective layer on reflective surfaces to improve the corrosion protection of vehicle headlight reflectors and other lamp reflectors that have an aluminum reflective coating. One disadvantage of the process taught by Zehender is that an extra coating over the metallization on the reflector is necessary to protect the reflective material. This extra coating is an unnecessary decorative coating which may not withstand high temperatures generated by a light bulb. Additionally, the extra coating is presented as particularly suitable as an additional clear layer for aluminum mirror surface reflectors.
U.S. Pat. No. 4,429,020 to Luch (hereinafter xe2x80x9cLuchxe2x80x9d) discloses an electroplating process of nickel-based and tin-based metal strata that allegedly provides a desirable composite article such as headlamps. The surface metal of the headlamp should be stable to maintain the desired color and continuity. The surface metal should also resist corrosion, cracking and other undue deterioration. This electro-plating process is lengthy and fails to provide sufficient high temperature protection against discoloration. Furthermore, this process typically requires additional manufacturing steps in the production of bulb shields.
One of ordinary skill in the art will appreciate that it would be desirable to provide a bulb shield with certain resistive qualities that generally avoid discoloration of the surface of the bulb shield.
It would also be desirable to provide a bulb shield comprising a corrosive resistant compound.
It would also be desirable to provide a high temperature deterioration resistant bulb shield for use in vehicle lighting.
It would also be desirable to provide a bulb shield with a structure that may be manufactured at low costs.
It would also be desirable to provide a bulb shield that has a structural strength to withstand vibration that is typically encountered in the vehicle lighting environment.
In one aspect of the present invention, a method of forming a vehicle lighting device metal part is provided. The method comprises forming a deterioration resistant Nickel Chromium Iron alloy composition into at least a portion of a metal part having a cup portion and a connector and electropolishing the metal part. A treatment is provided onto at least a portion of the metal part.
In an alternative arrangement, an automotive lighting metal part is provided. The lighting metal part comprises a cup portion having an inner surface and an outer surface. A connector is rigidly coupled to the cup portion, wherein at least a portion of the cup portion comprises a deterioration resistant Inconel(copyright) alloy composition.
In yet another arrangement, a method of shielding a lighting device is provided. The method comprises the steps of providing a bulb shield, the bulb shield having a cup portion for covering a lighting device and a connector rigidly affixed to the cup portion for coupling the bulb shield onto a housing of the lighting device. The bulb shield is mounted onto the lighting device, wherein at least a portion of the bulb shield is comprised of a deterioration resistant alloy composition.
These as well as other features and advantages of the present invention will become apparent to those of ordinary skill in the art by reading the following detailed description, with appropriate reference to the accompanying drawings.